Lvl 90 monk with 15 k achievements points (class change)

Maybe it's not a question for this particular forum, but there's a guy in my previous guild that plays on monk and has 15 k achievements points with some of them gained 2-3 years ago.
I haven't played for one year, now I'm getting back and want to start a monk. Have they introduced a class change or something and how on earth this guy managed to do this? Or I am not getting something and being a noob?

"Oh, who does my hair? You might have heard of my stylist. It's called the Void!"
"No matter how much you plead I will not sprout tentacles or turn into a giant eyeball. Well, I might. But not because you asked!"

Maybe it's not a question for this particular forum, but there's a guy in my previous guild that plays on monk and has 15 k achievements points with some of them gained 2-3 years ago.
I haven't played for one year, now I'm getting back and want to start a monk. Have they introduced a class change or something and how on earth this guy managed to do this? Or I am not getting something and being a noob?

Achievements went account wide. However you can still see number of "personal" achievement points of exact character, going to Guild -> Roster -> Achievement Points. My main has 12,250 achv pts but when I log on level 80 alt it says barely few hundred.

And class change isn't going to happen, because how technically it would be possible? If I change my hunter to warrior, will the warrior still wear agility mail gear and therefore be total useless? Or will it get converted into same ilvl warrior counterparts? Then there's spec problem, classes often use 2-3 sets of gear. Let players choose to have their epics transformed into tanking set, or plate DPS? Or let's just mail them whole new gearset, while enchanters can DE old epic gear and therefore make legit gold store? This gets more silly with each sentence, hopefully it will never happen.

It's not hard nor time consuming to level any class to 85 now. Last five levels are bit painful when doing it N-th time, but still nothing like Van WOW where it took 3x longer to level 1-60 than now it takes 1-90.